Some vehicles (especially hybrid vehicles) incorporate fuel systems which are pressurized during operation of the vehicle. Prior to refueling of these vehicles, the fuel system pressure must be reduced to (or below) a predetermined level, so that the fuel cap may be removed without the possibility of fuel ejecting from the fuel tank. In some systems, to prevent access to the fuel cap prior to sufficient fuel system depressurization, a locking mechanism may be coupled to the fuel door. The locking mechanism maintains the fuel door in a closed condition until the fuel system is sufficiently depressurized to open the fuel cap.
The fuel door may be opened by a user actuating a button or knob located in the passenger compartment. Actuation of the fuel door release initiates a fuel system depressurization process. When the pressure has fallen to an acceptable level, the fuel door opens automatically or may be opened by the user. However, after actuation of the fuel door release, a user is not aware of how much time will elapse before the fuel door may be opened, the status of the depressurization process, or even if fuel system depressurization is occurring. This may cause user frustration. Also, users unfamiliar with operation of the fuel system may not understand why the fuel door is not opening as soon as the release is actuated. Such users may attempt to open the fuel door manually prior to depressurization, or they may assume that the fuel door release is malfunctioning.